Gas and air filters



Filed Nov. 12, 1963 J. R. AUCKLAND GAS AND AIR FILTERS 5 Sheets-Sheet 1 g 1 P t I c MA I i ,10 1 E -41 FIGS 4 INVENTaR J HN R. AUCKLAND June 27, 1967 J. R. AUCKLAND 3,327,458

GAS AND AIR FILTERS Filed Nov. 12, 1963 5 SheetsSheet 9 I NVEN 70R J HN R- AUCKLAND y r v t A6598.

June 7, 1967 J. R. AUCKLAND 3,327,458

GAS AND AIR FILTERS Filed Nov. 12, 1963 5 Sheets-Sheet 5 l L LL.

INVENTOR JOHN R. AUCKLAND United States Patent 3,327,458 GAS AND AIR FILTERS John Raymond Auckland, Guildford, Surrey, England, assiguor to Vokes Limited, Surrey, England Filed Nov. 12, 1963, Ser. No. 323,007 1 Claim. (Cl. 55-341) This invention concerns improvements in gas and air filters usch as are used, for example, in air conditioning.

There are known filters which employ fibrous laps or webs of material supported upon open framework usually in zig-zag formation.

Servicing of such filters is often a laborious business, taking up a considerable time and the invention is directed to the provision of filters and replacement elements which simplify the process.

According to the invention I provide a gas or air filter comprising a frame supporting (within open-ended boxlike walls) a substantially V-shaped supporting grid within which a preformed bag of filtering material is stretchable by gas flow, the said bag being attachable by readily releasable fasteners at its open end to the inlet side of the said frame or grid.

The invention also comprises gas or air filter bags which are preformed from suitable material and are adapted to fill out under gas flowing within supporting grids, which bags carry at least one part of readily detachable fastening means at their open ends for connection to the inlet ends of such grids.

In preferred forms of the invention the open end of a bag is turned back on itself over the edge of the frame or grid, and in such cases the releasable fasteners may be carried as to one part on the bag and as to the other part on the grid or frame. Alternatively, if suitable slots or holes are made available in the frame or grid, both parts of the fasteners may be carried by the bag and be interengaged through the slots or holes after folding over the lip of the frame or bag.

The readily releasable fasteners may be of any conventional type, but among those that appear most suitable are press-button fasteners, hook and eye fasteners, swivelling head stud fasteners and spring clip fasteners.

It will be appreciated that, where the open end of the filter bag is folded over the inlet end of the frame or grid, gas or air flow will tend to press the material of the bag tightly against the lip of the open end and form a good seal.

Multiple frameworks and grids may be arranged alongside or above one another to provide for desired flow capacity.

The invention is illustrated in the accompanying drawings of one preferred form of filter which is now described as an example of the invention. In the drawings:

FIG. 1 is a plan view of a base frame assembly showing four filter bag support frames in position.

FIG. 2 is an end view of FIG. 1 in the direction of the arrow A.

FIG. 3 is an end view of FIG. 1 in the direction of the arrow B.

FIG. 4 is a section through a single bag support frame.

FIG. 5 is a plan view of a filter bag.

FIG. 6 is a section to enlarged scale on line C--C of FIG. 5.

Referring first to FIGS. 1 to 3, a base frame 1 of pressed sheet metal is square in shape and of dished construction.

Four spigots or flanges 2 of radiussed rectangular shape are fitted about four similarly shaped slots in the frame 1.

Each spigot carries a series of eight female parts of press stud fasteners 3.

A filter bag support frame 4 is fitted within each slot in the base frame 1.

Referring to FIG. 4 it will be seen that the end wires 5 of the support frames are bent outwardly at 6, and, as can be envisaged from FIG. 1, these bent portions are inserted in clips 7 on the base frame.

A clip 8 is shown in FIG. 4 for spacing the two walls of the support frame, but in practice it is prefer-red to use a freely hinger connector at this point so that individual frames may be folded flat for transport and be erected by the user. It will be observed that, in the absence of a fixed connection of the ends of the element 8, this, in itself, comprises a hinged connection.

A filter bag 12 is shown in FIG. 5 and such a bag is fitted with a series of eight male part fasteners 9. As shown in FIG. 6 a loop or tab 10 is stitched to the edge of the bag 12 (which is reinforced along such edge by tape 11) adjacent to each fastener part.

The edge of each bag 12 is turned over the appropriate spigot 2 (as shown diagrammatically in FIG. 2) and the fastener parts are engaged.

While releasable fastening means such as snap fasteners have been described as a preferred form of releasable fastener, it is to be understood that the other forms of fastener referred to above can equally well be employed, and it is possible to use wire, tape or other suitable filaments as ties to secure the filter bag ends to the spigots. In such circumstances the spigots must be modified by the provision of an outwardly turned lip or the like to ensure proper retention of the bag.

I claim:

A gas and air filter comprising a base frame of sheet material having a series of elongated apertures formed therein, spigot-like flanges extending from one face of the base frame and being provided with peripherally spaced snap fastener elements on their outer sides arranged around each of the elongated apertures, a pair of opposed grid panels fixed to extend from the opposite side of the base frame in alignment with the longer side of each aperture and sloped toward each other to a point of inter connection to form a truncated, wedge-shaped cage, a bag being made of filter material and being dimensioned such that it is permitted to open within and to adopt a complementary wedge shape to that of a pair of said opposed grid panels upon passage of gas therethrough and to permit an open mouth of the bag to be turned back over one of said spigot-like flanges, each bag being mounted between a pair of the opposed grid panels, the panels being formed of longitudinal and transverse wires and being hinged together at one end to form a substantially V-shaped support frame, the ends of the pairs of grid panels opposite the hinges being secured to the spigot-like flanges and having wire ends bent and releasably engaged with clips on said base for supporting the V-sectioned support frames adjacent said apertures, a reinforcing tape folded over the edge and surrounding the bag mouth and secured in engagement with the inner and outer bag surfaces, a series of snap fastener elements spaced around the periphery of said mouth releasabl'y locking the periphery of the bag in engagement with complementary elements on the spigot-like flange when the mouth of the bag is folded over the edge of the flange, and a tab secured to the bag adjacent each fastener element and provided with a loop projecting beyond the mouth of the bag for finger insertion to pull and unlock the adjacent fastener element.

(References on following page) References Cited UNITED STATES PATENTS Williams 210-448 Hageter.

Eisenkramer.

Hoy 210-485 X Kogler et a1 210-474 X Jordahl et a1. 55-341 X Birkholz 55-374 Beadle 248-101 X Dalzell 248-101 Seymour.

Vance.

4 Brace 55-357 X Slayter. Brace 55-374 X Sylvan. Hoffberger 210-473 Berly 55-341 Russo et a1. 248-101 X FOREIGN PATENTS Great Britain.

HARRY B. THORNTON, Primary Examiner.

D. TALBERT, Assistant Examiner. 

